How to Do Email Validation in PHP | Go4PHP

Email validation is an essential aspect of web development, especially when it comes to handling forms and user inputs on your website. By ensuring that the email addresses provided by users are valid, you can prevent errors, enhance data integrity, and protect your site from malicious activities. In this article, we’ll walk you through how to do email validation in PHP using several techniques. Whether you’re a beginner or an experienced developer, this guide will provide you with a comprehensive understanding of how to perform this critical task in PHP.

Why Email Validation Is Important

Before diving into the technical aspects, let’s quickly explore why email validation in PHP is so important:

1. Security: Ensuring that the email addresses entered by users are legitimate helps in safeguarding your website from spammers and fraudsters. Invalid or fake emails can open the door to unwanted registrations and other security threats.
2. Improved User Experience: When you validate emails on the front end or the backend, users will know right away if their input is incorrect. This leads to a smoother and more user-friendly experience.
3. Data Integrity: Accurate email addresses are critical for communication, especially for newsletters, password recovery, and account verification. Proper validation helps ensure that the data entered is correct and usable.

Common Methods of Email Validation in PHP

1. Using the filter_var() Function

PHP offers a built-in function filter_var() that makes email validation incredibly simple. This function checks whether an email address is valid according to the standards set by the internet.

Here’s an example of how you can use this function:

The FILTER_VALIDATE_EMAIL filter checks if the email is in the correct format, but it doesn’t check whether the domain actually exists or if the email address is deliverable.

2. Regular Expressions (Regex) for More Control

If you need more control over the structure of the email address, regular expressions (regex) provide a more robust solution. A common regex pattern used to validate email addresses is:

This regex ensures that the email follows the basic structure of an email address, such as “localpart@domain.com“, but it doesn’t ensure the email domain is reachable.

3. DNS Check for Domain Validation

To enhance the validation process, you can perform a DNS check to verify whether the domain in the email address exists. This can be done using the checkdnsrr() function in PHP:

This check ensures that the domain is valid and has an MX (Mail Exchange) record, which is essential for email communication.

4. Using PHP’s filter_var() with DNS Check

If you want to combine both the simplicity of filter_var() and the additional domain check, here’s an approach that validates both the format and the domain:

5. Using Third-Party Libraries for Comprehensive Validation

If you need even more sophisticated email validation, you can opt for third-party libraries. One such popular library is Email Verifier, which checks not only the format and domain but also the deliverability of the email address.

Here’s how to use it in PHP:

1. Install the library using Composer:

2. Use the library in your PHP code:

This approach helps in verifying whether an email address is real, not just formatted correctly.

Best Practices for Email Validation

1. Always Validate on the Server Side

While you might perform email validation on the client side (using JavaScript), never rely solely on it for security reasons. Always validate email addresses on the server side using PHP to ensure that you’re receiving clean and accurate data.

2. Provide Clear Error Messages

When an email address fails validation, provide the user with a clear and concise error message explaining why their input is incorrect. This improves the user experience and guides them to correct the error.

3. Avoid Over-Strict Validation

Sometimes, overly strict validation patterns may block valid email addresses. For example, email services like Gmail allow underscores in the domain part (e.g., “first_last@gmail.com“). Avoid overly restrictive validation patterns to ensure that your users’ email addresses are accepted.

4. Implement CAPTCHA for Extra Protection

If you’re worried about bot submissions, consider adding CAPTCHA functionality to your forms. CAPTCHA ensures that the form is being submitted by a human and not a bot.

Conclusion

Email validation in PHP is a critical task to ensure that your web forms are secure, user-friendly, and functional. By using simple built-in functions like filter_var(), regular expressions, and DNS checks, you can easily validate email addresses. For those seeking more advanced options, third-party libraries can provide even greater accuracy and deliverability checks.

Whether you’re building a small project or a large-scale application, performing proper email validation will help you maintain data integrity, improve user experience, and prevent potential security issues.

Remember, while client-side validation enhances usability, always ensure your server-side validation is robust. Combining both approaches ensures the best protection against invalid data.